FFmpeg编译4(1)

ffmpeg.c
ffmpeg.h

修改ffmpeg文件

修改刚刚拷贝的ffmpeg.c文件，找到int main(int argc, char **argv)函数，将其替换为int run(int argc, char **argv)
在修改后的run(int argc, char **argv) 末尾（retrun 之前）加上如上如下代码：

nb_filtergraphs = 0;
progress_avio = NULL;

input_streams = NULL;
nb_input_streams = 0;
input_files = NULL;
nb_input_files = 0;

output_streams = NULL;
nb_output_streams = 0;
output_files = NULL;
nb_output_files = 0;

并在ffmpeg.h文件末尾加上

int run(int argc, char **argv)；

再次打开ffmpeg.c文件，注释掉run(int argc, char **argv)下的所有exit_program函数，大致代码如下：

int run(int argc, char **argv)
{
int i, ret;
BenchmarkTimeStamps ti;

init_dynload();

register_exit(ffmpeg_cleanup);

setvbuf(stderr,NULL,_IONBF,0); /* win32 runtime needs this */

av_log_set_flags(AV_LOG_SKIP_REPEATED);
parse_loglevel(argc, argv, options);

if(argc>1 && !strcmp(argv[1], “-d”)){
run_as_daemon=1;
av_log_set_callback(log_callback_null);
argc–;
argv++;
}

#if CONFIG_AVDEVICE
avdevice_register_all();
#endif
avformat_network_init();

show_banner(argc, argv, options);

/* parse options and open all input/output files */
ret = ffmpeg_parse_options(argc, argv);
if (ret < 0);
// exit_program(1);

if (nb_output_files <= 0 && nb_input_files == 0) {
show_usage();
av_log(NULL, AV_LOG_WARNING, “Use -h to get full help or, even better, run ‘man %s’\n”, program_name);
// exit_program(1);
}

/* file converter / grab */
if (nb_output_files <= 0) {
av_log(NULL, AV_LOG_FATAL, “At least one output file must be specified\n”);
// exit_program(1);
}

// if (nb_input_files == 0) {
// av_log(NULL, AV_LOG_FATAL, “At least one input file must be specified\n”);
// exit_program(1);
// }

for (i = 0; i < nb_output_files; i++) {
if (strcmp(output_files[i]->ctx->oformat->name, “rtp”))
want_sdp = 0;
}

current_time = ti = get_benchmark_time_stamps();
if (transcode() < 0);
// exit_program(1);
if (do_benchmark) {
int64_t utime, stime, rtime;
current_time = get_benchmark_time_stamps();
utime = current_time.user_usec - ti.user_usec;
stime = current_time.sys_usec - ti.sys_usec;
rtime = current_time.real_usec - ti.real_usec;
av_log(NULL, AV_LOG_INFO,
“bench: utime=%0.3fs stime=%0.3fs rtime=%0.3fs\n”,
utime / 1000000.0, stime / 1000000.0, rtime / 1000000.0);
}
av_log(NULL, AV_LOG_DEBUG, “%“PRIu64” frames successfully decoded, %“PRIu64” decoding errors\n”,
decode_error_stat[0], decode_error_stat[1]);
if ((decode_error_stat[0] + decode_error_stat[1]) * max_error_rate < decode_error_stat[1]);
// exit_program(69);

// exit_program(received_nb_signals ? 255 : main_return_code);

nb_filtergraphs = 0;
progress_avio = NULL;

input_streams = NULL;
nb_input_streams = 0;
input_files = NULL;
nb_input_files = 0;

output_streams = NULL;
nb_output_streams = 0;
output_files = NULL;
nb_output_files = 0;

return main_return_code;
}

新建ffmpeg-invoke

在jni文件下新建一个ffmpeg-invoke.cpp的c++文件，将如下代码写入

#include <jni.h>
#include <string.h>
#include “android/log.h”

#define LOGD(…) __android_log_print(ANDROID_LOG_DEBUG, “ffmpeg-invoke”, VA_ARGS)

extern “C”{
#include “ffmpeg.h”
#include “libavcodec/jni.h”
}

extern “C”
JNIEXPORT jint JNICALL
Java_com_coder_ffmpeg_jni_FFmpegCmd_run(JNIEnv *env, jclass type, jint cmdLen,
jobjectArray cmd) {
//set java vm
JavaVM *jvm = NULL;
env->GetJavaVM(&jvm);
av_jni_set_java_vm(jvm, NULL);

char *argCmd[cmdLen] ;
jstring buf[cmdLen];

for (int i = 0; i < cmdLen; ++i) {
buf[i] = static_cast(env->GetObjectArrayElement(cmd, i));
char *string = const_cast<char *>(env->GetStringUTFChars(buf[i], JNI_FALSE));
argCmd[i] = string;
LOGD(“argCmd=%s”,argCmd[i]);
}

int retCode = run(cmdLen, argCmd);
LOGD(“ffmpeg-invoke: retCode=%d”,retCode);

return retCode;

}

需注意的是 Java_com_coder_ffmpeg_jni_FFmpegCmd_run 中 com_coder_ffmpeg_jni表示FFmpegCmd所在你Android项目的位置。

新建Android.mk

在jni文件夹下，新建Android.mk的文件，将如下代码拷贝，但是需要注意的是将 LOCAL_C_INCLUDES路径替换成你源码所在位置。

// 将此处的路径改为你ffmepg源码所在位置
LOCAL_C_INCLUDES := /home/anjoiner/Documents/AnJoiner/ffmpeg

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := libavdevice
LOCAL_SRC_FILES := prebuilt/libavdevice.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavutil
LOCAL_SRC_FILES := prebuilt/libavutil.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libswresample
LOCAL_SRC_FILES := prebuilt/libswresample.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libswscale
LOCAL_SRC_FILES := prebuilt/libswscale.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavcodec
LOCAL_SRC_FILES := prebuilt/libavcodec.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavformat
LOCAL_SRC_FILES := prebuilt/libavformat.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavfilter
LOCAL_SRC_FILES := prebuilt/libavfilter.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libpostproc
LOCAL_SRC_FILES := prebuilt/libpostproc.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg-invoke

LOCAL_SRC_FILES :=ffmpeg-invoke.cpp
cmdutils.c
ffmpeg_filter.c
ffmpeg_opt.c
ffmpeg_hw.c
ffmpeg.c

// 将此处的路径改为你ffmepg源码所在位置
LOCAL_C_INCLUDES := /home/anjoiner/Documents/AnJoiner/ffmpeg

LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid -lm -pthread -L$(SYSROOT)/usr/lib
LOCAL_SHARED_LIBRARIES := libavdevice libavcodec libavfilter libavformat libavutil libswresample libswscale libpostproc

include $(BUILD_SHARED_LIBRARY)

新建Application.mk

在jni文件夹下，新建Application.mk并将如下代码拷贝进入

APP_ABI := armeabi-v7a
APP_PLATFORM := android-21
APP_OPTIM := release
APP_STL := stlport_static

外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传

到此基本上的配置已经完成，然后在jni文件下运行ndk-build

/home/anjoiner/Documents/AnJoiner/build/jni# /home/anjoiner/Documents/AnJoiner/ffmpeg/ndk/ndk-build

当出现如下代码就表示成功了

[armeabi-v7a] SharedLibrary : libffmpeg-invoke.so
[armeabi-v7a] Install : libffmpeg-invoke.so => libs/armeabi-v7a/libffmpeg-invoke.so
[armeabi-v7a] Install : libpostproc.so => libs/armeabi-v7a/libpostproc.so
[armeabi-v7a] Install : libswresample.so => libs/armeabi-v7a/libswresample.so
[armeabi-v7a] Install : libswscale.so => libs/armeabi-v7a/libswscale.so

测试

新建一个支持C++项目，注意包名需是上述ava_com_coder_ffmpeg_jni_FFmpegCmd_run中的com.coder.ffmpeg。
在jni的同级目录下，会生成一个libs的目录，将这个目录下的armeabi-v7a文件拷贝到你所在的Android项目中的app/src/main/jniLibs下
新建一个jni的文件目录，在此目录下新建一个FFmpegCmd

/**

@author: AnJoiner
@datetime: 19-7-30
*/
public class FFmpegCmd {
static {
System.loadLibrary(“avdevice”);
System.loadLibrary(“avutil”);
System.loadLibrary(“avcodec”);
System.loadLibrary(“swresample”);
System.loadLibrary(“avformat”);
System.loadLibrary(“swscale”);
System.loadLibrary(“avfilter”);
System.loadLibrary(“postproc”);
System.loadLibrary(“ffmpeg-invoke”);
}

private static native int run(int cmdLen, String[] cmd);

public static int runCmd(String[] cmd){
return run(cmd.length,cmd);
}
}

拷贝进来run方法名会出现红色，不用管他,

在我们的MainActivity中进行调用，此方法是将音频进行剪切

public class MainActivity extends AppCompatActivity {

// Used to load the ‘native-lib’ library on application startup.
static {
System.loadLibrary(“native-lib”);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
100);
}

// Example of a call to a native method
TextView tv = findViewById(R.id.sample_text);
tv.setText(stringFromJNI());

findViewById(R.id.btn_test).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
ffmpegTest();
}
});
}

/**

A native method that is implemented by the ‘native-lib’ native library,
which is packaged with this application.
*/
public native String stringFromJNI();

private void ffmpegTest() {
new Thread() {
@Override
public void run() {
long startTime = System.currentTimeMillis();
String input =
Environment.getExternalStorageDirectory().getPath() + File.separator +
“DCIM” + File.separator + “test.mp3”;
String output =
Environment.getExternalStorageDirectory().getPath() + File.separator +
“DCIM” + File.separator + “output.mp3”;

String cmd = “ffmpeg -y -i %s -vn -acodec copy -ss %s -t %s %s”;
String result = String.format(cmd, input, “00:00:30”, “00:00:40”, output);
FFmpegCmd.runCmd(result.split(" "));
Log.d(“FFmpegTest”, “run: 耗时：” + (System.currentTimeMillis() - startTime));
}
}.start();

}

如果上述步骤不出错，基本没什么问题，在资料的参考下，我也弄了好几天，但幸好结果还是好的～

使用 NDK-r20 编译FFmpeg

前面使用过老版本NDK-r14b编译FFmpeg，其实质是通过gcc去进行编译，但是最新的NDK版本中已经不使用gcc去编译，而是使用clang去进行编译．这里贴上最新配置文件代码

下载最新版本NDK-r20
下载FFmpeg-4.2.1

#!/bin/bash

清空上次的编译

make clean
#你自己的NDK路径.
export NDK=/home/anjoiner/Android/Sdk/ndk-bundle
TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64/
API=29

function build_android
{
echo “Compiling FFmpeg for $\ --prefix=$ PREFIX
–enable-neon
–enable-hwaccels
–enable-gpl
–enable-postproc
–enable-shared
–enable-jni
–enable-mediacodec
–enable-decoder=h264_mediacodec
–disable-static
–disable-doc
–enable-ffmpeg
–disable-ffplay
–disable-ffprobe
–enable-avdevice
–disable-doc
–disable-symver
–cross-prefix= $CROSS_PREFIX \ --target-os=android \ --arch=$ ARCH
–cpu= $\ --cc=$ CC
–cxx= $\ --sysroot=$ SYSROOT
–extra-cflags=”-Os -fpic $OPTIMIZE_CFLAGS" \ --extra-ldflags="$ ADDI_LDFLAGS"
$ADDITIONAL_CONFIGURE_FLAG
make clean
make
make install
echo “The Compilation of FFmpeg for $CPU is completed”
}

#armv8-a
ARCH=arm64
CPU=armv8-a
CC= $TOO L C H A I N / bin / aa rc h 64 - l in ux - an d ro i d$ API-clang
CXX= $TOO L C H A I N / bin / aa rc h 64 - l in ux - an d ro i d$ API-clang++
SYSROOT= $NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot CROSS_PREFIX=$ TOOLCHAIN/bin/aarch64-linux-android-
PREFIX= $(pw d) / an d ro i d /$ CPU
OPTIMIZE_CFLAGS=“-march=$CPU”
build_android

#armv7-a
ARCH=arm
CPU=armv7-a
CC= $TOO L C H A I N / bin / a r m v 7 a - l in ux - an d ro i d e abi$ API-clang
CXX= $TOO L C H A I N / bin / a r m v 7 a - l in ux - an d ro i d e abi$ API-clang++
SYSROOT= $NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot CROSS_PREFIX=$ TOOLCHAIN/bin/arm-linux-androideabi-
PREFIX= $(pw d) / an d ro i d /$ CPU
OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU "
build_android